(x+2)(4x-5)=-3
4x²-5x+8x-10+3=0
4x²+3x-7=0
D=3²-4*(-7)*4=9+112=121
x(1) = -3+√121/2*4 = -3+11/8 = 8/8 = 1
x(2) = -3-√121/2*4 = -3-11/8 = - 14/8 = -7/4
Ответ: - 7/4; 1.
3/4x²-2/5x=4/5x²+3/4 x≠0
3/4x²-2/5x-4/5x²-3/4=0
(15-8x-16-15x²)/20x²=0
(-1-8x-15x²)/20x²=0
-1-8x-15x²=0 |*(-1)
1+8x+15x²=0
D=8²-4*15=64-60=4
x(1) = -8+√4/15*2 = -8+2/30 = -6/30 = -1/5
x(2) = -8-√4/15*2 = -8-2/30 = -10/30 = -1/3
Ответ: - 1/5; -1/3.